The Increasing Burden of Imported Chronic Hepatitis B — United States, 1974–2008

Abstract

BackgroundWithout intervention, up to 25% of individuals chronically infected with hepatitis B virus (HBV) die of late complications, including cirrhosis and liver cancer. The United States, which in 1991 implemented a strategy to eliminate HBV transmission through universal immunization, is a country of low prevalence. Approximately 3,000–5,000 U.S.-acquired cases of chronic hepatitis B have occurred annually since 2001. Many more chronically infected persons migrate to the United States yearly from countries of higher prevalence. Although early identification of chronic HBV infection can reduce the likelihood of transmission and late complications, immigrants are not routinely screened for HBV infection during or after immigration.MethodsTo estimate the number of imported cases of chronic hepatitis B, we multiplied country-specific prevalence estimates by the yearly number of immigrants from each country during 1974–2008.ResultsDuring 1974–2008, 27.9 million immigrants entered the U.S. Sixty-three percent were born in countries of intermediate or high chronic hepatitis B prevalence (range 2%–31%). On average, an estimated 53,800 chronic hepatitis B cases were imported to the U.S. yearly from 2004 through 2008. The Philippines, China, and Vietnam contributed the most imported cases (13.4%, 12.5%, and 11.0%, respectively). Imported cases increased from an estimated low of 105,750 during the period 1974–1977 to a high of 268,800 in 2004–2008.ConclusionsImported chronic hepatitis B cases account for approximately 95% of new U.S. cases. Earlier case identification and management of infected immigrants would strengthen the U.S. strategy to eliminate HBV transmission, and could delay disease progression and prevent some deaths among new Americans.

Hepatitis B Virus and Hepatitis C Virus Infections in United States-Bound Refugees from Asia and Africa

“…24 Since the adoption of universal vaccination against HBV, the rates of incident HBV infection in the United States have declined by more than 80%, to 1.5 per 100,000 individuals in 2009 25 ; however, the number of persons with chronic HBV infection in the United States is still substantial. The major contributing factor to the continuing endemicity of chronic hepatitis B is importation by already HBV-infected foreign-born individuals 8 ; the refugees studied here and found positive for HBV DNA contribute to that endemicity.…”

“…4,6,7 It is estimated that over 90% of new cases of CHB in the United States are among foreign-born persons. 8 Because persons who are chronically infected serve as viral reservoirs and may transmit infection to susceptible individuals and to protect the personal health of infected individuals, they should receive additional testing and be considered for treatment, monitored for progression of disease, and receive prevention counseling. Accordingly, the CDC recommends that all adults, including refugees, who were born in regions of the world with 2% prevalence of HBV infection be tested for hepatitis B surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc), or antibodies to hepatitis B surface antigen (anti-HBs) (http:// www.astho.org/Programs/Infectious-Disease/Refugee-Health/ ARHC-Medical-Screening-Recommendations/).…”

Prevalence of Major Risk Factors and Use of Screening Tests for Cancer in the United States

“…Approximately 700,000 to 2.2 million people are living with chronic HBV infection in the United States, and an estimated 38,000 people are newly infected each year (82)(83)(84). Most new HBV cases (95%) in the United States are among people who immigrated from countries where HBV infection is more common (85). Vaccination against HBV has been the primary prevention strategy in reducing prevalence of the virus (82,86).…”

Factors Associated with Hepatitis B Knowledge Among Vietnamese Americans: A Population-Based Survey

“…Up to 83.3% have been exposed [5] compared to 3.8% of the general population [6], and Vietnamese Americans accounted for 11.0% of chronic HBV cases [7]. The liver cancer incidence rate among Vietnamese Americans is six times that of non-Hispanic whites [8].…”